Potential Sensitive Probes

This type of fluorescent probe is especially useful for the tracking and imaging of membrane potential across excitable cells. Membrane potential is a result of differences in K+, Na+, and Cl- concentrations inside and outside the cells and is controlled by active transport processes. It plays a mayor role in neurobiology, muscle contraction, and cell signaling.

The use of microelectrodes is commonly applied, but spatial resolution is limited and sampling requires a certain time. Imaging of fluorescent probes overcomes these limitations. Potential sensitive probes differ in their response time and amplitude of signal. If the response time needs to be minimized, fast-responding probes have to be used. Typically styrylpyridinium dyes are fast-responding, although their signal amplitude is not as strong as slower-responding probes.